Door lock

ABSTRACT

A door lock includes a cylinder with a core installed in a door. A flat finger is connected with the core. A latch is movably provided in a latch hole of the door and the flat finger extends through the latch. An inner cover is provided at an interior surface of the door opposite to the cylinder and has a plurality of sink holes defined therethrough for a plurality of first screws extending through the sink holes and engaged in the threaded holes. An outer cover is provided outside the inner cover to conceal the inner cover. A knob is provided outside the outer cover and has a hollow shaft extending through the outer cover and the inner cover and connected with the finger. Whereby, when the knob is turned, the latch can be extended or retracted to lock/unlock the door.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is related to a door lock, and more particularlyto a door lock which is convenient to adjust for installing properly.

2. Description of Related Art

Referring to FIGS. 9 and 10, a conventional door lock is composed of acore (91) received in a cylinder (90), a latch (92), a guard plate (93),a back cover (94), and a knob (95).

The cylinder (90), located at an exterior surface of a door (97), ismounted in a lock bole (971) defined through the door (97). The core(91) is received in the cylinder (90). The latch (92) is received in alatch hole (972) laterally defined in the door (97) and in communicationwith the lock bole (971). A faceplate (96) is mounted at a sidewall ofthe door (97), and the latch (92) can extend out from the faceplate(96). The guard plate (93) is provided in the lock hole (971) and at aninterior surface of the door (97). Two first screws (932), respectivelyextending through two first holes (931) in the guard plate (93), areengaged in the cylinder (90). The guard plate (93) is provided with aflat finger (911) extending through the latch (92) and into the core(91). The back cover (94) is mounted outside the guard plate (93) by twosecond screws (943) respectively extending through two second holes(942) in the back cover (94) and two third holes (933) in the guardplate (93) and engaged in the cylinder (90). The knob (95) is rotatablymounted in a fourth hole (941) in the back cover (94), and the finger(931) is received in the knob (95).

Therefore, turning the knob (95) can turn the core (91) and move thelatch (92) by means of the finger (931) to lock/unlock the door.

However, it is difficult to install the lock properly in one time, andthe movement of the latch (92) will not be smooth when it is in animproper status, so that adjustment is often needed and may involverepeated trial and error. Referring to FIG. 11, during the adjustment,because the first and second screws (932, 943) are engaged in thecylinder (90) through the guard plate (93) and the back cover (94)respectively, the second screws (943) must be first disengaged to detachthe back cover (94), and then the first screws (932) can be loosened foradjusting the guard plate (93). Thus, it is very inconvenient to attemptto adjust the lock. Furthermore, the installed door lock does not have anice appearance because heads of the second screws (943) exposed fromthe back cover (94) can be seen.

Therefore, the invention provides a door lock to mitigate and/or obviatethe aforementioned problems.

SUMMARY OF THE INVENTION

The main objective of the invention is to provide a door lock which isconvenient to adjust for proper installation.

Another objective of the invention is to provide a door lock with anattractive appearance.

Other objectives, advantages and novel features of the invention willbecome more apparent from the following detailed description when takenin conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded top sectional view of a first embodiment of a doorlock in accordance with the invention;

FIG. 2 is an exploded side sectional view of the door lock in FIG. 1;

FIG. 3 is a top sectional view of the door lock in FIG. 1;

FIG. 4 is a front view of FIG. 3;

FIG. 5 is a top sectional view of a second embodiment in accordance withthe invention;

FIG. 6 is a front view of FIG. 5;

FIG. 7 is a top sectional view of a third embodiment in accordance withthe invention;

FIG. 8 is a top sectional view of the door lock in FIG. 7 assembled inanother manner;

FIG. 9 is an exploded top view of a conventional door lock;

FIG. 10 is a top view of the conventional door lock in FIG. 9; and

FIG. 11 is a front view of the conventional door lock in FIG. 9.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIGS. 1-4, in a first embodiment in accordance with thepresent invention, a door lock has a cylinder (10) installed in a lockhole (61) of a door (60) and located at an exterior surface of the door(60). A core (11) with a key hole (not shown or numbered) is received inthe cylinder (10). A flat finger (12) received in the lock hole (61) ofthe door (60) has a front end connected with the core (11). A pluralityof threaded holes (13) is defined in the cylinder (10) around the core(11).

A latch (20) is movably received in a latch bole (62) laterally definedin the door (60), and the finger (12) extends through the latch (20). Afaceplate (22) with a latch opening (not numbered) is mounted on asidewall of the door (60), and a tongue (21) of the latch (20) canextend out of or retract into the latch opening when the core (11) andthe finger (12) are turned.

An inner cover (30) is provided at an interior surface of the door (60)and has a plurality of sink holes (31) defined therethrough andcorresponding to the threaded holes (13). Multiple first screws (33)respectively extend through the sink holes (31) and are engaged in thethreaded holes (13) to fasten the inner cover on the door (60). Theinner cover (30) further has a first central opening (32) definedtherethrough.

An outer cover (40) is provided outside the inner cover (30) and has asecond central opening (41) defined therethrough and aligned with thefirst central opening (32). Especially referring to FIGS. 2 and 4, theinner cover (30) has at least two lugs (34) formed around the firstcentral opening (32) and respectively engaged in two apertures (42)defined around the second central opening (41) of the outer cover (40)to fasten the outer cover (40).

A knob (50) is provided outside the outer cover (40) and has a ringedrecess (51) defined at an end facing the outer cover (40) and a shafthole (55) longitudinally defined therein. A resilient member (52) isreceived in the recess (51) and abuts against the outer cover (40). Ahollow shaft (53) extending through the first opening (32) and thesecond opening (41) has a rear end (531) positioned in the shaft hole(55) and an open front end (532) accessible for a rear end of the finger(12) to be inserted in the hollow shaft (53). A threaded aperture (56)is radially defined through the shaft hole (55), and a second screw (57)is engaged in the threaded aperture (56) to further fasten the shaft(53) in the shaft hole (55). Moreover, a sleeve (58) is provided outsidethe front end (532) of the shaft (53) and has an opening (581) for thefinger (12) extending therethrough. Thus, when the knob (50) is turned,the finger (12) can be driven to rotate to move the latch (20).

In this embodiment, the cross sections of the shaft (53) and the shafthole (55) are rectangular. It should be understood by those skilled inthe art that the cross sections can be other polygonal shapes.

According to the embodiment described as above, it is easy to remove theouter cover (40) from the inner cover (30) because there is not a screwprovided therebetween. Therefore, during assembling of the door lock, ifthe latch (22) or the finger (12) is not in the proper position, it isconvenient to detach the outer cover (40) and loosen the first screws(33) for adjusting the latch (22) and the finger (12). Furthermore, thefirst screws (33) are concealed in the outer cover (40), so that thedoor lock has a nice appearance.

In another embodiment as shown in FIGS. 5 and 6, the door lock furtherhas a guard plate (70) provided inside the inner cover (30). The guardplate (70) has a flange (71) received in the lock hole (61), and an edge(72) abutting a rim (35) of the inner cover (30). A plurality of firstholes (73) corresponding to the sink holes (31) of the inner cover (30)is defined through the guard plate (70) and the first screws (33)respectively extend through the first holes (73). A third central hole(74) is defined through guard plate (70) and aligned with the firstcentral hole (32) for the shaft (53) extending therethrough.

The door lock described as above also can be adjusted easily by means ofsimply removing the outer cover (40) and directly loosening the firstscrews (33).

Referring to FIG. 7, in a third embodiment of the invention, the doorlock has a guard plug (80) provided inside the inner cover (30). Theguard plug (80) has a first step (81) and a second step (82), wherein adiameter of the first step (81) is smaller than a diameter of the secondstep (82). The first step (81) is received in the lock hole (61), andthe second step (82) is received in the inner cover (30). A shoulder(83) is formed between the first step (81) and the second step (82) andabuts the rim (35) of the inner cover (30). The guard plug (80) furtherhas a plurality of second holes (85) respectively aligned with the sinkholes (31) for the first screws (33) extending through the second holes(85). A fourth central hole (84) is defined through the guard plug (80)for the shaft (53) extending therethrough.

Referring to FIG. 8, for matching the lock hole (61) with a differentdiameter, the guard plate (80) can be arranged with the second step (82)received in the lock hole (61) and the first step (81) received in theinner cover (30).

By using the guard plug (80), the door lock can be installed in the door(60) more securely and have a high safety feature.

It is to be understood, however, that even though numerouscharacteristics and advantages of the present invention have been setforth in the foregoing description, together with details of thestructure and function of the invention, the disclosure is illustrativeonly, and changes may be made in detail, especially in matters of shape,size, and arrangement of parts within the principles of the invention tothe full extent indicated by the broad general meaning of the terms inwhich the appended claims are expressed.

1. A door lock comprising: a cylinder installed in a lock hole of a doorand located at an exterior surface of the door, the cylinder having acore rotatably received therein, a flat finger connected with the core,and a plurality of threaded holes defined in the cylinder around thecore; a latch movably provided in a latch hole of the door and the flatfinger extending through the latch; an inner cover provided at aninterior surface of the door opposite to the cylinder, the inner coverhaving a plurality of sink holes defined therethrough and correspondingto the threaded holes, a plurality of first screws extending through thesink holes and engaged in the threaded holes, and a first centralopening defined therethrough; an outer cover provided outside the innercover and concealing the inner cover, the outer cover having a secondcentral opening defined therethrough and aligned with the first centralopening; a knob provided outside the outer cover, the knob having aresilient member against the outer cover provided at an end facing theouter cover, and a hollow shaft extending through the first opening andthe second opening and having a front end connected with the finger anda rear end engaged with the knob; and a guard plug provided inside theinner cover and having a first step and a second step, wherein adiameter of the first step is smaller than a diameter of the secondstep, and the first step and second step are selectively received in thelock hole and the inner cover, a shoulder formed between the first stepand the second step and abutting the rim of the inner cover, a pluralityof second holes respectively aligned with the sink holes for the firstscrews extending through the second holes, and a fourth central holedefined through the guard plug for the shaft extending therethrough,whereby, when the knob is turned, the latch can be extended or retractedto lock/unlock the door.
 2. The door lock as claimed in claim 1 furthercomprising a guard plate provided inside the inner cover and having aflange received in the lock hole, an edge abutting a rim of the innercover, a plurality of first holes corresponding to the sink holes of theinner cover defined through the guard plate and the first screwsrespectively extending through the first holes, a third central holedefined through guard plate and aligned with the first central openingfor the shaft extending therethrough.
 3. The door lock as claimed inclaim 1, wherein the knob has a ringed recess defined at the end facingthe outer cover and the resilient member is received in the recess. 4.The door lock as claimed in claim 1, wherein the inner cover has atleast two lugs respectively engaged in at least two apertures of theouter cover to fasten the outer cover.
 5. The door lock as claimed inclaim 4, wherein the lugs are formed around the first central opening,and the apertures are defined around the second central opening.
 6. Thedoor lock as claimed in claim 1, wherein the knob further has a shafthole longitudinally defined therein, and the rear end of the shaft ismatingly positioned in the shaft hole.
 7. The door lock as claimed inclaim 6, wherein the cross sections of the shaft hole and the rear endof the shaft are polygonal.
 8. The door lock as claimed in claim 6,wherein the knob further has a threaded aperture radially definedthrough the shaft hole, and a second screw engaged in the threadedaperture to fasten the shaft in the shaft hole.
 9. The door lock asclaimed in claim 1 further comprising a sleeve provided outside thefront end of the shaft and having an opening for the finger extendingtherethrough.